1. Field of the Invention
This invention relates to a disc-like rotatable article having vibration damping means and comprising a body with a work region (e.g. having teeth or one or more cutting blades) adapted to interact with another article (e.g. a workpiece or another disc-like rotatable article).
2. Description of the Prior Art
The reduction of noise occurring during idling running and particularly during the working or chip removing process of rotating parts, in particular tools such as saw blades, constitutes an urgent but difficult problem. This applies particularly to tools for the treatment of wood and synthetic resin, but also for metal-working, for example light-metal saws, tools for the machining of steel, and so on.
It has been found that a reduction of the noise may be obtained for a circular saw tool if the tool body forming the so-called stock blade is provided on at least one side, preferably on both sides, with a damping layer formed by an adhesive and a cover arranged on it as a counter-element, namely by damping the saw-blade vibrations causing the noise. The layer in the form of an adhesive not only has the purpose of attaching and retaining the cover on the respective part of the tool, but at the same time it fulfils an important function in respect of vibration damping. The externally excited or self excited vibrations of the rotating tool cause respective thrust motions between the cover and the tool body proper (stock blade), whereby corresponding shear stresses are produced in the damping layer.
It is important for the use of tools of such construction that the elements located on the damping layers retain their position and are not released by the loads occurring. On the other hand, however, as high a damping as possible is to be attained. Therefore demands are involved which contradict each other to a large extent.
There is therefore a need to overcome existing difficulties and defects and to provide an article of the kind referred to above which has advantageous properties, and to construct it in such a manner that it can comply with a variety of requirements. This applies in particular in respect of favourable stiffness conditions, mechanical strength, effective protection of the damping system, and reliable holding-together of the parts associated therewith, while at the same time attaining a highly satisfactory damping effect. With all this, the loads to be expected in practical use, particularly those on the outer or lateral portions of the article, should be absorbed reliably.